The organization of legumin films deposited on different solid substrates using the Langmuir-Blodgett technique has been studied by X-ray photoelectron spectroscopy (XPS). The XPS data provide information on the identity of the chemical elements present as well as on chemical bonding. From the decomposed XPS C 1s spectra, the different types of carbon (peptidic, aliphatic etc.) have been identified. The variation in atomic ratios as a function of the take-off angle shows a structural orientation of the protein films in which the hydrophobic aliphatic amino acids are at the external surface whereas the hydrophilic amino acids are oriented towards the solid substrate. Moreover, the attenuation in the S 2p signal intensity with decreasing take-off angle due to the protein layer suggests that the adsorbed protein forms a continuous overlayer on a glass substrate whereas the weak dependence of the F 1s signal intensity with the take-off angle suggests an incomplete coverage of the polytetrafluoroethylene substrate.